A need exists for improved reservoir flooding compositions, surfactants, and methods for enhanced oil recovery. In particular, a need exists for such improved compositions and surfactants which can be used to: (1) increase oil recovery from the reservoir; (2) reduce adsorption of the surfactant on the rock formation surface; (3) better analyze and understand the geology of the reservoir during trials, (4) detect and quantify the adsorption of the flooding surfactant on the formation rock; (5) understand other phenomena occurring in the reservoir during enhanced oil recovery; and (6) optimize final commercial flooding operations and other enhanced oil recovery procedures performed in the reservoir.